The manufacturers of Norvelo, a European emergency contraception pill, just announced that they'll be adding a warning label stating that the drug is completely ineffective for women weighing over 175 pounds and begins to lose effectiveness for anyone over 165 pounds (Mother Jones). That's a huge deal for anyone on this side of the pond relying on Plan B, which is virtually identical in dosage and chemical makeup to Norvelo.

Also known as the "morning after pill," Plan B is currently available in the US to everyone (no matter how old you are) without a prescription. It's meant to be a backup method for preventing pregnancy in case your normal birth control method (condoms, The Pill, etc) fails (CDC). At the moment, the FDA is still reviewing whether or not a similar warning label needs to be placed on Plan B and generic versions of the same pill (CNN).

In the meantime, the Centers for Disease Control is stressing that Plan B should be used as a backup method, not as your main method of preventing pregnancy, stating: "The best way to reduce the risk of unintended pregnancy among women who are sexually active is to use effective birth control correctly and consistently" (CNN).